Quantifying Glacial Erosion Rates, Magnitudes, and Paleotopography in the Coast Mountains, British Columbia

不列颠哥伦比亚省海岸山脉冰川侵蚀速率、震级和古地形学的量化。托德A.在过去的12年里，一场全球性的科学辩论随之而来，即气候变化或构造运动是否为加速山脉隆起的出现或现实提供了动力。 密歇根大学的这个为期三年的项目将测试一个假设，即较冷的气候，更具体地说是冰川作用，增加了地形起伏和山脉的最大高度，从而在过去的1000万年里产生了加速隆起的外观。 以前测试这一假设的尝试由于缺乏对百万年时间尺度上冰川侵蚀的分布和数量的了解而受到阻碍。 这项研究将整合地球化学数据（低温热时计）与三维计算机模型，以量化在南部海岸山脉，不列颠哥伦比亚省的冰川侵蚀历史的新数据收集和建模的整合，这项研究将涉及几个步骤。(1)两个季节的实地考察将在南部海岸山脉约25 x25公里的区域内提供60个新样本。 (2)需要两年的计算机程序开发来修改现有的三维计算机模型，以模拟不断变化的地形。该模型将预测各种构造和侵蚀情景下暴露的样品年龄。 (3)最后两年将应用一个逆向计算机模拟程序来确定冰川侵蚀历史的范围，以及满足测量的地球化学样品年龄的古冰川前地形。 这三个步骤的结果将通过重建海岸山脉冰川作用前的山脉地形来检验所述假设，并评估冰川作用是否增加了地形起伏。 除了解决科学界长期存在的问题外，这项研究还将提供一个博士学位。对于一个研究生来说。 主要研究员和研究生将在K-12学校科学课上定期进行关于“冰川和冰河时代”的讲座，至少有一名本科生将参与并指导研究过程。

Quantifying Glacial Erosion Rates, Magnitudes, and Paleotopography in the Coast Mountains, British ColumbiaP.I. Todd A. Ehlers - University of MichiganEAR-0309779In the last 12 years a global scientific debate has ensued over if climate change or tectonics provided the impetus for the appearance, or reality of accelerated mountain uplift. This three year project at the University of Michigan will test the hypothesis that cooler climates, and more specifically glaciation, increase the topographic relief and maximum height of mountain ranges, thereby producing the appearance of accelerated uplift in the last ~10 Million years. Previous attempts to test this hypothesis have been hampered by a lack in understanding of the distribution and amount of glacial erosion over million-year time scales. This study will integrate geochemical data (low-temperature thermochronometers) with three-dimensional computer models to quantify the glacial erosion history in the southern Coast Mountains, B.C.The integration of new data collection and modeling for this study will involve several steps. (1) Two seasons of fieldwork will provide 60 new samples within a ~25x25 km area of the southern Coast Mountains. (2) Two years of computer program development are needed to modify an existing three-dimensional computer model to simulate evolving topography. The model will predict exposed sample ages under a variety of tectonic, and erosional scenarios. (3) The last two years will apply an inverse computer-modeling program to determine the range of glacial erosion histories, and ancient preglacial topographies, that satisfy the measured geochemical sample ages. The results from these three steps will test the stated hypothesis by reconstructing the mountain topography prior to glaciation in the Coast Mountains and assess if glaciation increased topographic relief. In addition to addressing a long-standing problem in the scientific community, this study will also provide a Ph.D. for one graduate student. The principle investigator and graduate student will give regular talks in K-12 school science classes on 'glaciers and ice ages' and at least one undergraduate student will be involved, and mentored in the research process.